WM_POWERBROADCAST
The
WM_POWERBROADCAST message is sent to an application to notify it of
power-management events.
dwPowerEvent = (DWORD) wParam;
dwData = (DWORD) lParam;
Parameters
dwPowerEvent
Event
notification message. This parameter can be one of the following values:
|
Value |
Meaning |
|
PBT_APMBATTERYLOW |
Battery
power is low. |
|
PBT_APMOEMEVENT |
OEM-defined
event occurred. |
|
PBT_APMPOWERSTATUSCHANGE |
Power
status has changed. |
|
PBT_APMQUERYSUSPEND |
Request for
permission to suspend. |
|
PBT_APMQUERYSUSPENDFAILED |
Suspension
request denied. |
|
PBT_APMRESUMECRITICAL |
Operation
resuming after critical suspension. |
|
PBT_APMRESUMESUSPEND |
Operation
resuming after suspension. |
|
PBT_APMSUSPEND |
System is
suspending operation. |
dwData
Function-specific
data. For most messages, this parameter is reserved and not used.
However, if wParam
is one of the resume notifications (PBT_APMRESUME*), the lParam
parameter can specify the PBTF_APMRESUMEFROMFAILURE flag. This flag indicates
that a suspend operation failed after the PBT_APMSUSPEND message was sent.
Return Values
Return TRUE
to grant a request.
Return
BROADCAST_QUERY_DENY to deny a request.